The easiest meals are things you buy in the supermarket
- ready made quiches, tarts, pizzas, pies, all come in easy veggie/vegan versions, probably not quite as good value or as healthy as things you cook yourself but v. good on lazy days! Or with a little more effort but still some 'cheating', things like a ready made tomato pasta sauce with some roast veg and cheese, or a partially-home made pizza or tart, where you buy a ready made pizza base or jus-roll puff pastry, and top with your favourite toppings are great and super easy and quick.
In the last 10 years, meat substitutes have also improved beyond all recognition in terms of taste and availability so do explore the world of veggie sausages, burgers, 'chicken' substitutes, quorn/soy mince etc as well - use these just as you would the meaty equivalent. I also like ready-made falafels in a wrap or with some bulgar wheat or rice for a quick and easy meal (yes I know it isn't very hard to make your own falafel but the ready made kind are very good and a lot quicker than getting out the chickpeas, blender and frying pan to DIY).
On days you are up for more cooking, soups, chillis, curries, tagines and stews made with beans and pulses are really healthy, cheap and delicious, and you can make up a big batch and freeze portions for later, they will only improve - good suggestions on this thread or look at BBC good food. Lots of mediterreanean type dishes (risottos, pasta dishes, paella, minestrone) also don't require meat, anything which was historically peasant food can quite often have the meat left out or substituted with grains/pulses....